This invention relates generally to an improved AC adapter of the type used to provide a DC voltage to an associated electronic instrument from an AC supply voltage. More particularly, this invention relates to a compact and low profile power supply adapter for plug-in connection to a standard electrical socket, without obstructing or interfering with adjacent electrical sockets of a standard duplex or quad wall outlet or the like. The invention is particularly designed for use with electronic instruments in a medical environment, and further includes means for removably mounting the power supply adapter onto or in close association with the instrument when not in use.
Modern medical treatment facilities utilize a variety of sophisticated electronic instruments in the course of patient diagnosis and treatment. As one common example, electronically operated medication infusion pumps are commonly used for administering one or more selected medical fluids to a patient at a prescribed flow rate and time schedule. Such fluid medication infusion pumps and other electronic equipment require a source of electrical power to maintain the instrument in a desired operational state.
In this regard, many electronic instruments designed for medical as well as nonmedical uses are constructed to operate on a DC power supply which can be obtained in the alternative from batteries or by use of an appropriate transformer and rectifier connected to a standard AC power source. In this latter case, the AC adapter frequently comprises a power supply adapter designed for direct plug-in connection to an AC power supply outlet, with an elongated cord extending between the plug-in adapter and the associated electronic instrument used to supply DC to the instrument.
In the past, plug-in power supply adapters have included a relatively compact housing or case having the components of an AC adapter mounted therein. Conductive prongs associated with the transformer components have protruded outwardly from the adapter case for plug-in connection in the manner of a standard electrical plug with an associated AC power supply receptacle, such as one socket of a standard duplex or quad wall outlet, or a multisocket strip, or the like.
Accordingly, the adapter case essentially comprises the body of an electrical plug for manual grasping in the course of plug-in and unplugging movements. However, the physical size and shape of the adapter case has typically exceeded the width and height of a conventional electrical plug, such that the adapter case partially overlies and therefore obstructs access to adjacent electrical sockets. For example, in a conventional duplex or quad wall outlet, plug-in connection of a single AC/DC power supply adapter to one of the electrical sockets normally obscures and thus precludes access to all of the remaining electrical sockets in the wall outlet. Additional electrical devices which may be desired or necessary, especially in a medical treatment facility must therefore be plugged into a different wall outlet.
Moreover, in a medical treatment environment, it is often necessary to transport electronic medical instruments from one place to another. For example, fluid infusion pumps are often transported with patients throughout different areas of a hospital or the like, or from one patient room to another for use with different patients as the need arises. While such instruments may be battery powered for short term operation in a mobile environment, it is important that the electrical power cord and associated power supply adapter remain with the instrument so that normal operation can be resumed quickly and easily by mere plug-in connection of the adapter to a power supply outlet.
However, transport of the power supply adapter and associated cord with the instrument poses particular problems in that the adapter is relatively heavy and thus difficult to transport with the instrument in a secure and stable manner and/or can become easily separated from the instrument and is thus relatively easily misplaced.
There exists, therefore, a significant need for an improved power supply adapter of the plug-in type wherein the adapter can be plugged into a standard electrical socket without interfering with access to adjacent sockets, and further wherein the adapter includes means for convenient and stable mounting in a stored position in association with an electronic instrument for transport purposes. The present invention fulfills these needs and provides further related advantages.